Hondata

The Honda ECU, like your Honda engine is a very well designed piece of equipment made to work in many cars under many varying conditions of temperature and altitude. This tech article looks at the functions of the ECU and and what makes it work so well.

*** Warning *** This article is technical in nature and may cause you to learn something.



http://www.hondata.com/techecuanatomy.html

Doug

Arturbo

Wow I did learn something. No in other words the Apex AFC hack isnt really worth it after all. Very good info.

art

lucas569

doug i got some quick questions,

1. is it TRUE that when you reset the ecu you have to let it run for 10 min in order for it to "reprogram" itself and relearn its parameters or can you just drive the car and go and it will relearn no matter what?

2. what causes an ecu to go into limp mode? i had a p-28 that wouldnt let me go past 3000 rpms (like i fried it) replaced the ecu and everything was all good, and was this ecu repairable? (i threw it out)

EE_Chris

http://www.tech2tech.net/training/chpt_01.pdf

Just a little something to add to a great thread.

And there are about 30+ chapters, so just replace the /chpt_xx.pdf with the various chapters #'s and your gold.


[Modified by EE_Chris, 2:38 PM 3/25/2002]

Herminator

what would I do without honda-tech. Great stuff!

ssblue

great article!

VTC_CiViC

Doug, that was an excellent ariticle!! Thanks for bringing out the finer points of the Honda ECU's, amazing how well Honda designed these things!

HXMan

Doug, I am curious. Has your company done any research on the OBD2 ECU's? In the future do you think it may be possible to do the same thing with the OBD2 ecus as you can do with the OBD1 units? Do you know how long it will be if something like this is going to happen?

I am asking this because the OBD2 ECU's process faster, and have alot more diagnostic abilities then the OBD1 ECU. Overall, I would have to say the OBD2 ECU is much more capable. Plus, many people wounldn't then have to buy that OBD2 to OBD1 harness.

falcongsr

Doug gets asked this question a lot.

The problem with OBD2 is that the programmable memory and the processor is integrated into one chip, and its a one-time programmable chip, so every time you want to make a change, its gonna cost you $200 for a new chip. compare this with a obd1 that can use a EEPROM that sells between $5 and $20 and can be reprogrammed thousands of times.

I think i heard that RSXs had flash memory that can be reprogrammed. there may be a future in tweaking the next gen ECUs, but thats not much help to us with integras and pre 01 civics.

HXMan

Hmmm....if a cheaper chip could be sourced, it would be a viable option. Maybe someone will figure a way how to get around this. Something like a chip with an ability to remove the memory portion without having to buy a completly new chip each time. A $200 dollar first investment, and $5-20 dollars for every update would be acceptable.

Hondata

Only one company makes the part needed, and it is not just a chip. It includes the complete microprocessor as well, which is why it is expensive.

OBD IIs process faster, but a lot of that processing time is used monitoring emissions parameters.

lucas569 - letting your car idle for 10 minutes means it probably learns more quickly, but you can probably drive immediately.

DirtyLude

Another good website is:
http://www.autoshop101.com/

Go to technical articles. A good book on automotive electronics is Understanding Automotive Electronics by William B. Ribbens

SOHCArchangel

excellent article

Arturbo

Good stuff, Im gonna print all 30chapter out!!

art

falcongsr

yeah. i didnt get any work done today. thanks a lot ee_chris!

BLKCRX

wow !! great info. !!
now i have more info... to use as a selling point for hondata out here in Australia.. i knew vtec afc's suxed now i can backup my argument.

Regards James

rioninja

please explain why you think this?

Arturbo

http://www.hondata.com/techecuanatomy.html
All your answers are there.

art

ThePunk

Thank you for taking the time to put that information together...
Every little bit helps!

willyboyK20

how long would it take for the ecu to overide a piggyback's fuel controller's settings.
If that is the case then a piggyback fuel controller for a honda is useless if you plan on not getting a standalone.
That sucks for all us buget mined folks

DSF

I wouldn't totally agree with this (assuming I understand everything correctly ). The AFC hack really only does one thing. It's a voltage restriction on the MAP output signal. (I'm running the mod on a non-VTEC, so I won't get into VTEC crossover as it brings in other issues.) Yes, the ecu can modify it own fuel tables, but only so much. That's why it has trouble idling anything above 310cc/min injectors on it's own. With the amount of "fuel correction" the AFC hack uses, I don't see how the ecu could compensate that much to negate it. It would be like saying upping fuel pressures doesn't work (pump/FMU set-up...not that it's a good idea either). And if part-throttle fueling does become an issue, the old TPS hack (WOT TPS signal @boost onset) could be used to utilize the ecus static (I assume they're static) open loop fueling tables in conjuction with the AFC's correction.

Is this the right way...no. Does it "work"...sure (AFC hack in my budget CRX). Of course Hondata is an excellent solution (I'm using it in my Civic). But, for the budget/ghetto minded, I feel the AFC hack is a viable alternative to pump/FMU set-ups. Let's see, I removed the VAFC from my Civic because I got Hondata. I got a set of DSM 450's for $50. About $35 for electronic parts and a pressure switch for the TPS hack. And $85 for a universal MSD BTM. So for $170 I got myself a working, relatively tunable, boost friendly fuel/ignition system. Not too bad

This isn't inteded as a flame. Just my thoughts put into words

rioninja

Exactly what i was gonna say, i just didnt have time to type it

riceboy

good article, but I have a question for anybody that knows about the Hondata system, if I was to get a 3B, could I buy the HondaLogger and ROM Editor (particularlly the ROM Editor) and add those features to the 3B? I seriously doubt I can, just thought I'd ask.

dustin

That would be 4b then =P

Xerxes

yeah that is just stage 4b, and yes, you can upgrade from 3b to 4b at a later date when you have the money

-Xerxes